VY-58
Animal Health

Cooperative Extension Service
Purdue University
West Lafayette, IN 47907

Cattle WartsBovine Papillomatosis

Warts are caused by infection with the contagious bovine
papillomavirus. Four types of the virus are known to produce skin
lesions. All have been described as hardy. Two of the viral types
cause most of the warts found on the head and neck of cattle. They
will survive in the environment for weeks or months if protected by
pieces of tissue such as a shed wart or bits of tissue on a halter.
Because of the infectious nature of the wart virus, animals with warts
are disqualified from shows and exhibitions.

Calves are most susceptible; few cases of warts seen in cattle
over 2 years of age. Occasionally, warts are found on the teats of
lactating dairy cows. Calves are easily infected the papillomavirus
entering the cut or abraded skin. All too frequently calves are
inadvertently infected when tattooed or ear tagged for identification
purposes. In fact, it is not unusual to find an entire tattoo
overgrown with a mass of warts. Warts will appear 1 to 6 months after
inoculation with the virus. Warts often spread from the ear to other
sites on the head and neck.

Papillomavirus is widely distributed in cattle. Cattle are the
main source and natural reservoir of infection by the virus; but,
halters, ropes, and instruments can serve as a potential source of
infection. Not all animals carrying the virus will have warts. It can
be transmitted from the inapparent carrier to the susceptible calf.

Prevention

Commercial vaccines are available; and if used as directed, they
may help prevent warts in cattle not previously infected. Autogenous
vaccines are prepared from chemically treated warts taken from animals in
a herd. In fact, the autogenous vaccine is more apt to have the strain
or type of papillomavirus causing the wart problem in a herd than some
of the commercial vaccines.

Instruments and tack used on infected animals should be
disinfected before use on other animals. The infected animal may not
have visible warts, but they may still contaminate equipment. Tattoo
or tagging pliers can be disinfected between use on calves, with a 2
to 4% solution of formaldehyde. Dilute the liquid formalin 1 to 18 for
a 2% solution or 1 to 9 for the 4% solution. Rinse off blood or tissue
from the pliers before immersing in the formaldehyde. Maintain two
sets of the instruments and alternate them in use thereby providing
adequate time in the formaldehyde to inactivate the virus. Rinse them
before using and wear examination gloves or rubber household gloves to
protect hands from irritation. Tack that has been in contact with
infected calves can also be disinfected with formaldehyde.

Treatment

Warts usually shrink and drop off after a few months. The
spontaneous recovery has probably been the basis for the alleged
effectiveness of many regimes of treatment-including several kinds of
oil, toothpaste of various brands, wart pinching, or twisting off
close to the base. Any of these appear to be successful if the warts
regress spontaneously.

Multiple injections of vaccines have been credited for being an
effective cure. Vaccines are considered to protect cattle, but they
have not been found to be of value in treatment. Warts can be removed
surgically with a scissors or a side cutter. Bleeding can be
controlled, if a problem, with silver nitrate applicator sticks. A
wound spray should be applied to prevent problems with flies. Healing
is rapid and the animals should be show-eligible in a few days.
Usually the warts do not recur.

Proper disinfection of tack, tagging pliers, and tattooing
instruments will prevent the spread of the wart virus.

RR 5/92

Reference to products in this publication is not intended to be an
endorsement to the exclusion of others which may be similar. Persons
using such products assume responsibility for their use in accordance
with current label directions of the manufacturer.

Cooperative Extension Work in Agriculture and Home Economics, State of
Indiana, Purdue University and U.S. Department of Agriculture
Cooperating. H.A. Wadsworth, Director, West Lafayette, IN. Issued in
furtherance of the Acts of May 8 and June 30, 1914. It is the policy
of the Cooperative Extension Service of Purdue University that all
persons shall have equal opportunity and access to our programs and
facilities.